隧道水平冻结施工引起地表冻胀的历时预测模型  

A duration prediction model of surface frost heave induced by tunnelling with horizontal freezing method

作　　者：蔡海兵[1,2] 彭立敏[1] 郑腾龙[2] 

机构地区：[1]中南大学土木工程学院,长沙410075 [2]安徽理工大学土木建筑学院,安徽淮南232001

出　　处：《岩土力学》2012年第6期1761-1768,共8页Rock and Soil Mechanics

基　　金：国家重点基础研究发展973计划(No.2011CB013802);住房和城乡建设部科学技术项目(No.2010-K3-16);安徽省自然科学基金项目(No.1208085QE87)

摘　　要：隧道水平冻结施工过程中,土体冻结引起体积膨胀,进而会在地表产生冻胀现象。实际工程一般采用多根冻结管形成冻结壁。冻结壁交圈前,地表冻胀由多个冻土柱的叠加膨胀变形引起;冻结壁交圈后,地表冻胀则由整个冻结壁的膨胀变形引起。鉴于此,考虑冻结壁的形成过程,基于随机介质理论,建立了隧道水平冻结施工引起地表冻胀位移的历时预测模型。同时对冻结外锋面半径和冻胀区域外半径这2个关键参数的取值方法进行了相关探讨。最后针对两个工程案例,采用该计算模型对地表冻胀位移进行分析,得到地表冻胀位移随时间的变化规律,并与现场实测结果相比较,验证了模型的可靠性。该模型应用于隧道水平冻结施工前、冻结期内任意时刻的地表冻胀位移预测,可为工程冻结实施方案的合理确定提供有效依据。In the process of tunnelling with horizontal freezing method,soil volume expansion caused by freezing can produce the phenomenon of surface frost heave.Multiple frozen pipes are usually used to form frozen wall in the actual engineering.Before the circle-crossing period of frozen wall,surface frost heave is induced by superimposed expansion deformation of multiple frozen columns.After the circle-crossing period of frozen wall,surface frost heave is induced by expansion deformation of the whole frozen wall.In view of this,considering the formation process of frozen wall and based on stochastic medium theory,a duration prediction model of surface frost heave induced by tunnelling with horizontal freezing method is presented.Two value methods of freezing outer front radius and frost heave region outer radius are discussed at the same time.Finally,aiming at two engineering cases,surface frost heave displacements are analyzed by calculation model.Variations of surface frost heave displacements with time are obtained,which are compared with field measured results to verify reliability of the model.The model is applied to surface frost heave displacements prediction at any time of freezing period before tunnelling with horizontal freezing method,and can provide effective reference for reasonable determining freezing implementation scheme.

关 键 词：隧道冻结 地表冻胀 冻结过程 预测模型 随机介质理论 

分 类 号：U445.555[建筑科学—桥梁与隧道工程]